"Until now, it was not known if the industry could continue to adapt this optical immersion technique to produce sharp features smaller than 32 nanometers. New materials required to make such small features were thought to be incompatible with each other or capable of yielding only indistinct, blurred patterns. As a result, in recent years contingency plans are being explored for switching sometime in the future to a radically different but much more expensive – and still unproven -- manufacturing method that uses soft-x-rays (also known as EUV, for extreme ultraviolet light)"
Interestingly, in the book by the guy who used to be the CEO of Intel (Moore, I think) he described an incident decades ago now (I believe it was that long ago) when the claim was being made that photolithography had reached its limit and it would be necessary to switch to X-rays to keep making chips smaller.
There was no sure answer to the question one way or the other. If this idea was right, and Intel's stuck with photolithography, they could be caught in a technological squeeze, a little like Kodak was. The problem was, making the shift to X-rays would have been incredibly expensive. If the idea was wrong, Intel might be destroyed due to wasting such a large amount of money.
In the event, Moore decided not to switch to X-ray technology. He guessed right.